With its 1,400-foot-tall slender condominium tower nearing completion, the developers of 111 W. 57th St. are ready to welcome retailers into its base along Billionaires’ Row.

JDS Development Group, Property Markets Group and Spruce Capital Partners have hired a Newmark RKF team to pitch its four stories of nearly 50,000 square feet to luxury retailers. To do so, brands will have to take a giant leap down that long block from Fifth Avenue to the new building that sits just west of Sixth Avenue — and where Angelo’s Pizza and a body spa are its neighbors, along with fellow wealthy tower mates in One57.

But they are also counting on more billionaires strolling in from the two new towers that are even farther west. These include Extell’s record-setting sky-high 1,550-foot-tall Central Park Tower that will house the new Nordstrom, and Vornado’s uber-luxe 220 Central Park South condo project, where more than $1 billion in sales were completed, including Ken Griffin’s $238 million penthouse purchase and Sting’s $66 million unit — and it has a Jean-Georges restaurant on the way.

The retail area at 111 W. 57th will combine the landmarked interior and cherub-filled rotunda of Steinway Hall’s former performance space with the modern, toothpick tower’s Art Deco-infused bronze and terra-cotta finishes.

Shoppers will enter the 8,000 square feet on the ground floor through either the rotunda or the adjacent new building, which includes a dramatic, six-story-high atrium.

An escalator brings visitors to a small mezzanine and then upward to the dramatic third floor. Here, ceilings are 15 to 39 feet high and there’s a 15,523-square-foot shopping area bathed in natural light from its windows on West 58th Street. The fourth floor has another 8,620 square feet of shopping.

The lower level includes 10,076 square feet expected to be targeted toward food and beverage — but may be more white tablecloth than food court.

The Newmark RKF team includes Jackie Totolo, Pierce Thompson, Adam Weinblatt, Alexandra Tennenbaum and Robert Cohen. No rental rates are available.

The upstairs condominium residences are expected to start closings in early 2020 and are being sold through Douglas Elliman. There are just 46 apartments, and availabilities range from a single floor of 4,492 feet for $18 million to the 74th floor duplex penthouse of 7,130 square feet for $57 million. Another penthouse is in contract for nearly its $58 million asking price.